CN116985374B

CN116985374B - An extruder and processing method for cable processing

Info

Publication number: CN116985374B
Application number: CN202311095049.5A
Authority: CN
Inventors: 张相洋
Original assignee: Anhui Zhongxun Cable Co ltd
Current assignee: Anhui Zhongxun Cable Co ltd
Priority date: 2023-08-28
Filing date: 2023-08-28
Publication date: 2025-12-30
Anticipated expiration: 2043-08-28
Also published as: CN116985374A

Abstract

This invention proposes an extruder and processing method for cable processing. The extruder includes a screw extruder and an extrusion die. The extrusion die is connected and installed at the discharge port of the screw extruder. The extrusion die includes a front die cavity, a rear die cavity, a central tube, a rotating cavity, and a rotation drive component. The front die cavity, rotating cavity, and rear die cavity are connected sequentially. The front die cavity has a first channel, the rotating cavity has a second channel, and the surface of the rear die cavity has a groove. The first channel, the second channel, and the groove are connected sequentially to form an extrusion cavity. The rotating cavity is rotatably connected to both the front and rear die cavities. The central tube is coaxially disposed within the extrusion cavity. The rotation drive component is fixedly connected to the rear die cavity, and its driving end is drively connected to the surface of the rotating cavity, enabling the rotation drive component to drive the rotating cavity to rotate. The processing method of this invention drives the rotating cavity to rotate, thereby circumferentially rotating and stirring the molten material within the extrusion die, improving the dispersion of the molten material within the extrusion die.

Description

Extruder for cable processing and processing method

Technical Field

The invention relates to the technical field of cable processing equipment, in particular to an extruder for cable processing and a processing method.

Background

The cable at least comprises a wire rod, an insulating layer and a protective layer, wherein the insulating layer and the protective layer are coated on the outer surface of the wire rod, in the prior art, the insulating layer and the protective layer of the cable are generally processed by adopting a mode of coextrusion of the wire rod and an insulating layer material or a protective layer material, specifically, the insulating layer material or the protective layer material is extruded into a die head with an annular cavity after being heated and melted, the wire rod is allowed to pass through the middle of the die head of the annular cavity, and the wire rod is compounded with an outer sleeve layer extruded from an annular extrusion opening after passing through the die head of the annular cavity, so that the processing of the cable is completed.

However, in the above-mentioned scheme, in the process of flowing into the annular cavity, the molten material extruded from the extruder generally flows and fills the die cavity under the action of pressure, and is limited by the shape of the annular cavity and the influence of the connection position between the extrusion port of the extruder and the cavity, so that the dispersibility and filling property of the molten material extruded into the die cavity are insufficient, which results in that the surface of the insulation layer and the protective layer of the extruded cable is easy to have defects, such as bubbles, gaps and interfaces generated by uneven distribution in the extrusion process, and the defects bring about potential safety hazards to the quality of the cable.

How to improve the dispersibility and filling property of the molten material in the extrusion die is one of the technical problems to be solved at present.

Disclosure of Invention

In view of the above, the present invention provides an extruder for processing a cable and a processing method thereof, which aim to improve the dispersibility of a molten material in an extrusion die head by improving the structure of the extruder.

The technical scheme is that the extruder for processing the cable comprises a screw extruder and an extrusion die head, wherein the extrusion die head is arranged at a discharge hole of the screw extruder in a communicated mode, the extrusion die head comprises a front die cavity, a rear die cavity, a central tube, a rotating cavity and a rotating driving piece, the front die cavity, the rotating cavity and the rear die cavity are sequentially connected, a first channel is arranged in the front die cavity, a second channel is arranged in the rotating cavity, a groove is arranged on the surface of the rear die cavity, the first channel, the second channel and the groove are sequentially communicated to form an extrusion cavity, a feeding hole is arranged on the side face of the rear die cavity, the feeding hole is communicated with the groove, one end of the first channel, which is far away from the rotating cavity, is an opening, the rotating cavity is respectively connected with the front die cavity and the rear die cavity in a rotating mode, the central tube is coaxially and coaxially arranged in the extrusion cavity, one end, close to the rear die cavity, of the central tube is fixedly connected with the rear die cavity, one end, close to the front die cavity, is communicated with the discharge hole, is separated from the discharge hole to form an annular outlet, the rotating driving piece is fixedly connected with the rear die cavity, the surface of the rotating driving piece is in a transmission connection with the rotating cavity, the rotating driving piece can drive the rotating driving piece to rotate.

In some embodiments, the inner surface of the second channel is axially provided with a helical protrusion.

In some embodiments, the first channel, the second channel, and the groove are all cylindrical, and the first channel, the second channel, and the groove are coaxially disposed and have the same inner diameter.

In some embodiments, the mold further comprises a connecting plate, and the front mold cavity and the rear mold cavity are fixedly mounted on the surface of the connecting plate.

In some embodiments, a first chamfer is provided on an end of the rotating cavity adjacent to the front mold cavity along the outer circumference, a second chamfer is provided on the inner side of the first channel along the circumference, and the first chamfer is in sliding fit with the second chamfer.

In some embodiments, the first thrust bearing further comprises a first chamfer on which an inner ring of the first thrust bearing is coaxially embedded, and a second chamfer on which an outer ring of the first thrust bearing is coaxially embedded.

In some embodiments, a third chamfer is circumferentially provided at an end of the rotating cavity adjacent the rear cavity, a fourth chamfer is circumferentially provided at an inner side of the groove, and the third chamfer is in sliding engagement with the fourth chamfer.

In some embodiments, the engine further comprises a second thrust bearing, an inner race of the second thrust bearing being coaxially embedded on the third chamfer, and an outer race of the second thrust bearing being coaxially embedded on the fourth chamfer.

In some embodiments, the rotary shaft further comprises a combustion nozzle fixedly mounted on the connection plate, and the air jet of the combustion nozzle is arranged opposite to the outer surface of the rotary cavity.

The invention also provides a processing method of the extruder based on the cable processing, which comprises the following steps that a wire rod is driven to be conveyed to one side of a discharge hole at a constant speed in a central tube, a screw extruder extrudes molten materials into an extrusion cavity, a rotary driving piece drives the rotary cavity to rotate and circumferentially drives and stirs the molten materials positioned in the rotary cavity, the molten materials are extruded from an annular outlet and then are coated on the surface of the wire rod, and the cable is obtained after cooling.

In the above processing method, optionally, the combustion nozzle may be turned on during the rotation of the rotating chamber, and the heating process may be performed on the rotating chamber.

Compared with the prior art, the extruder and the processing method for processing the cable have the following beneficial effects:

According to the invention, through improving the inner cavity structure of the die head of the extruder, the rotating cavity capable of rotating around the axis direction is arranged in the middle section of the extruding cavity, and when the molten material extruded from the screw extruder flows through the second channel of the rotating cavity, the molten material is rotationally stirred under the drive of intermolecular forces between different radial layers of fluid under the rotating action of the rotating cavity, so that the dispersion uniformity of the molten material in the extruding die head is improved.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is an isometric view of an extruder for cable processing in accordance with the present invention;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is an isometric view of an extrusion die section in an extruder for cable processing in accordance with the present invention;

FIG. 4 is an exploded view of FIG. 3;

FIG. 5 is a cross-sectional view of FIG. 3;

Fig. 6 is a sectional view of the partially exploded state of fig. 3.

In the figure, a 1-screw extruder, a 2-extrusion die head, a 3-connecting plate, a 4-first thrust bearing, a 5-second thrust bearing, a 6-combustion nozzle, a 21-front die cavity, a 22-rear die cavity, a 23-central tube, a 24-rotating cavity, a 25-rotating driving piece, a 211-first channel, a 2111-second chamfer surface, a 212-discharge hole, a 221-groove, a 2211-fourth chamfer surface, a 222-feed hole, a 241-second channel, a 242-first chamfer surface, a 2411-spiral protrusion and a 243-third chamfer surface are shown.

Detailed Description

The following description of the embodiments of the present invention will clearly and fully describe the technical aspects of the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience in describing and simplifying the description based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the invention belong. If the definitions set forth in this section are contrary to or otherwise inconsistent with the definitions set forth in the patents, patent applications, published patent applications and other publications incorporated herein by reference, the definitions set forth in this section are preferentially set forth in the definitions set forth herein.

As shown in fig. 1, in combination with fig. 2-6, the extruder for cable processing according to the present invention comprises a screw extruder 1 and an extrusion die head 2, the extrusion die head 2 is installed at a discharge port of the screw extruder 1 in a communicating manner, the extrusion die head 2 comprises a front die cavity 21, a rear die cavity 22, a central tube 23, a rotating cavity 24 and a rotating driving member 25, the front die cavity 21, the rotating cavity 24 and the rear die cavity 22 are sequentially connected, a cylindrical first channel 211 is provided in the front die cavity 21 in a penetrating manner, a cylindrical second channel 241 is provided in the rotating cavity 24 in a penetrating manner, a cylindrical groove 221 is provided on the surface of the rear die cavity 22, the first channel 211, the second channel 241 and the groove 221 are sequentially communicated to form an extrusion cavity, a feed port 222 is provided on a side surface of the rear die cavity 22, the feed port 222 is communicated with the groove 221, one end of the first channel 211 far from the rotating cavity 24 is an outlet 212, the rotating cavity 24 is respectively connected with the front die cavity 21 and the rear die cavity 22 in a rotating manner, the central tube 23 is coaxially provided in the extrusion cavity, one end of the central tube 23 near the rear die cavity 22 is fixedly connected with the rear die cavity 22 and one end of the rear die cavity 22, the central tube 23 is provided near the rear die cavity 22, the end of the central tube 23 is near the rear die cavity 22 is provided near the rear die cavity 212 and is connected with the rear die cavity 22 in a rotating driving member 25, near the front end of the rotating cavity 21 is connected with the rotating driving member 25, and is capable of rotating and connected with the rotating driving member 25.

In the above embodiment, the central tube 23 is coaxial with the extrusion cavity formed by connecting the front die cavity 21, the rotating cavity 24 and the rear die cavity 22, an annular extrusion channel is formed between the outer wall of the central tube 23 and the inner wall of the extrusion cavity, the feed port 222 introduces the melt in the screw extruder 1 into the annular extrusion channel, the melt dispersedly fills the space in the groove 221 under the action of pressure and gradually flows to the second channel 241 and the first channel 211 in sequence, in the conventional process, the flow process is driven by the extrusion pressure of the screw extruder 1, the melt is fluid, and the flow has a tendency to flow out of the annular extrusion channel along the shortest channel, so that there is a problem that the flow dispersion of the melt fluid in the annular extrusion channel is uneven, for example, the melt near the side of the feed port 222 is not easy to flow to the side far from the feed port 222. The rotation driving member 25 is used to drive the rotation cavity 24 to rotate around the axis, and in the rotation process, the molten material flowing through the second channel 241 is driven by the rotation of the inner wall of the second channel 241 to be rotationally mixed at the second channel 241, so that the molten material is uniformly mixed and dispersed in the second channel 241.

In some embodiments, the inner surface of the second channel 241 is axially provided with a helical protrusion 2411.

In the above embodiment, when the rotation chamber 24 rotates, the driving action of the molten material located in the second channel 241 is achieved by the viscosity action between the inner wall of the second channel 241 and the molten material, the stirring effect is relatively limited, and it is difficult for the stirring action to be formed between the layers of the molten material in the radial direction, in order to overcome this problem, the spiral protrusions 2411 of the auger shape are provided on the inner surface of the second channel 241, the spiral protrusion 2411 is arranged along the axial direction of the second channel 241, and the spiral protrusion 2411 can improve the exchange effect of the interlayer materials and promote stirring on one hand, and on the other hand, the auger-shaped spiral protrusion 2411 can play a role in pushing flow along the axial direction when stirring, so that the material exchange stirring of the molten materials at the axial position and the outer position is further enhanced.

In some embodiments, the height of the helical projection 2411 is preferably 1/3-2/3 of the distance between the inner wall of the second channel 241 and the outer wall of the center tube 23.

The screw protrusions 2411 with the above height can play a better stirring role, and the molten material is relatively not easy to adhere to the screw protrusions 2411 to block the channel.

In some embodiments, the first channel 211, the second channel 241, and the groove 221 are all cylindrical, and the first channel 211, the second channel 241, and the groove 221 are coaxially disposed and have the same inner diameter.

In the above embodiment, when the inner diameters are the same, the resistance is smaller during the flow of the material from the groove 221 into the first passage 211.

In some embodiments, the mold further comprises a connecting plate 3, and the front mold cavity 21 and the rear mold cavity 22 are fixedly installed on the surface of the connecting plate 3.

In the above embodiment, the connecting plate 3 is used to connect the front mold cavity 21, the rear mold cavity 22 and the rotating cavity 24, specifically, the three are connected with the connecting plate 3 through bolts, and the connecting plate 3 is used to connect the three, so that the disassembly, replacement and maintenance of the front mold cavity 21, the rear mold cavity 22 and the rotating cavity 24 can be realized.

In some embodiments, the end of the rotating cavity 24 adjacent to the front cavity 21 is provided with a first chamfer 242 along the outer circumference, and the inner side of the first channel 211 is provided with a second chamfer 2111 along the circumference, and the first chamfer 242 is in sliding fit with the second chamfer 2111.

In the above embodiment, since the rotating cavity 24 is rotationally connected with the front cavity 21, and the extrusion die 2 needs to bear a larger pressure, the dynamic sealing effect of the rotating connection part needs to be improved as much as possible in the rotating process, and chamfer surfaces are respectively provided on the outer periphery of the rotating cavity 24 and the inner periphery of the first channel 211 of the front cavity 21, and the chamfer surfaces are tapered surfaces, so that on one hand, the contact area of the sliding fit part can be improved, the sealing effect is good, and on the other hand, the tapered surfaces also have positioning and guiding effects, and can keep the axis alignment between the first channel 211 and the second channel 241.

In some embodiments, further comprising a first thrust bearing 4, an inner race of the first thrust bearing 4 is coaxially embedded over the first chamfer face 242, and an outer race of the first thrust bearing 4 is coaxially embedded over the second chamfer face 2111.

In the above embodiment, when the surfaces are in contact, the friction force is large, in order to avoid the problems of large friction force and serious abrasion caused by direct contact friction of materials, the first thrust bearing 4 is adopted to connect two chamfer surfaces, specifically, the first thrust bearing 4 is conical, and has a conical outer ring surface and a conical inner ring surface, and the two conical surfaces are used for carrying out matching connection with the first chamfer surface 242 and the second chamfer surface 2111 in decibels.

In some embodiments, the first thrust bearing 4 may be a sealed thrust bearing.

In some embodiments, to achieve a mating connection with the first thrust bearing 4, corresponding positioning grooves are formed in the surfaces of the first chamfer surface 242 and the second chamfer surface 2111 in the circumferential direction, and the positioning grooves are respectively used for embedding an inner ring and an outer ring of the first thrust bearing 4.

In some embodiments, the end of the rotating cavity 24 near the rear mold cavity 22 is provided with a third chamfer 243 along the outer circumference, and a fourth chamfer 2211 is provided along the circumference on the inner side of the groove 221, and the third chamfer 243 is in sliding fit with the fourth chamfer 2211.

Similarly, in order to improve the dynamic sealing effect, a certain centering effect is achieved, and a conical chamfer is adopted to perform sliding fit between the rotating cavity 24 and the rear die cavity 22.

In some embodiments, the second thrust bearing 5 is further included, an inner ring of the second thrust bearing 5 is coaxially embedded on the third chamfer 243, and an outer ring of the second thrust bearing 5 is coaxially embedded on the fourth chamfer 2211.

In the above embodiment, the mounting manner and structure of the second thrust bearing 5 are the same as those of the first thrust bearing 4, and the second thrust bearing 5 is used as a rotational connector, so that the third chamfer 243 is prevented from directly sliding contact with the fourth chamfer 2211, and the sliding resistance is reduced.

In some embodiments, the surfaces of the third chamfer 243 and the fourth chamfer 2211 are also provided with annular grooves for mating with the inner ring and the outer ring of the second thrust bearing 5, and are connected by embedding, thereby improving the sealing property.

In some embodiments, the second thrust bearing 5 may be a sealed thrust bearing.

In some embodiments, the device further comprises a combustion nozzle 6, wherein the combustion nozzle 6 is fixedly arranged on the connecting plate 3, and the air jet opening of the combustion nozzle 6 is arranged opposite to the outer surface of the rotating cavity 24.

In the above embodiment, since the rotation chamber 24 needs to be maintained to rotate, crystallization is easily caused in the melt during rotation, and in order to avoid this problem, the combustion nozzle 6 is used to heat the rotation chamber 24 in order to improve the stirring effect during rotation, thereby heating the melt inside and improving the fluidity of the melt.

In some embodiments, an annular protrusion structure is provided on a side of the inner side surface of the first channel 211 adjacent to the second channel 241, the annular protrusion structure protruding from the inner side wall of the first channel 211.

In the above embodiment, the annular protrusion structure is used for blocking and disturbing the material layer on the side of the molten material flowing into the first channel 211, which is close to the inner wall of the first channel 211, so that the forced plug flow stirring effect is achieved, unlike the spiral stirring effect of the spiral protrusion 2411, when the molten material flows through the annular protrusion structure, the flow channel is suddenly reduced, the pressure in the fluid is increased, the flow velocity is increased, and meanwhile, the process is favorable for eliminating the structures such as bubbles and air gaps in the fluid, further improving the surface and the internal quality of the extruded material, and reducing the internal defects.

In some embodiments, a second annular protrusion is integrally formed on the outer surface of the central tube 23 and on the side of the annular protrusion structure near the outlet 212, and the second annular protrusion and the annular protrusion structure form a labyrinth-like structure.

In the above embodiment, the second annular bulge is matched with the annular bulge structure, so that the molten material can be extruded and stirred again, the defects of internal bubbles or air gaps and the like are promoted to be eliminated, and meanwhile, the stirring effect is enhanced.

In some embodiments, the side of the second annular projection adjacent to the outlet 212 smoothly transitions with the outer surface of the center tube 23.

In the above embodiment, the smoothly transitioned second annular projection facilitates filling the extruded molten material in the first channel 211, avoiding underfilling.

In some embodiments, the method of processing the extruder of the above embodiments comprises:

The driving wire rod is conveyed to one side of the discharge hole 212 at a constant speed in the central tube 23, the screw extruder 1 extrudes molten material into the groove 221, the molten material gradually flows through the second channel 241 and the first channel 211 under the pressure effect and finally is extruded from the discharge hole 212, in the process of flowing through the second channel 241, the rotation driving piece 25 is started to drive the rotation cavity 24 to rotate, thereby rotationally stirring the molten material flowing through the second channel 241, the extruded molten material is sleeved outside the wire rod, and the cable is obtained after stretching and cooling.

In other embodiments, the combustion nozzle 6 may be turned on, and the rotating chamber 24 may be heated by the combustion nozzle 6 to maintain the temperature inside the rotating chamber 24 within a target temperature range, so as to maintain good fluidity of the molten materials.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1. An extruder for cable processing, comprising a screw extruder (1) and an extrusion die (2), wherein the extrusion die (2) is connected and installed at the discharge port of the screw extruder (1), characterized in that the extrusion die (2) comprises a front die cavity (21), a rear die cavity (22), a central tube (23), a rotating cavity (24), and a rotating drive component (25), wherein the front die cavity (21), the rotating cavity (24), and the rear die cavity (22) are connected in sequence, wherein the front die cavity (21) is provided with a first channel (211), and the rotating cavity (24) is provided with a first channel (211). The cavity has a second channel (241) and a groove (221) on its surface. The first channel (211), the second channel (241), and the groove (221) are connected in sequence to form an extrusion cavity. The side of the rear cavity (22) has a feed port (222) that is connected to the groove (221). The end of the first channel (211) away from the rotating cavity (24) is opened as a discharge port (212). The rotating cavity (24) is rotatably connected to the front cavity (21) and the rear cavity (22). A central tube (23) is coaxially disposed within the extrusion cavity. One end of the central tube (23) near the rear mold cavity (22) passes through the rear mold cavity (22) and is fixedly connected to it. The other end of the central tube (23) near the front mold cavity (21) passes through the discharge port (212) and forms an annular outlet with the discharge port (212) at intervals. A rotating drive component (25) is fixedly connected to the rear mold cavity (22). The driving end of the rotating drive component (25) is connected to the surface of the rotating cavity (24) for transmission. The rotating drive component (25) can... The drive rotating cavity (24) rotates. The inner surface of the second channel (241) is provided with a spiral protrusion (2411) along the axial direction. On the inner side surface of the first channel 211 near the second channel (241), there is an annular protrusion structure. The annular protrusion structure protrudes from the inner wall of the first channel (211). On the outer surface of the central tube (23) and on the side of the annular protrusion structure near the discharge port (212), a second annular protrusion is integrally formed. The second annular protrusion and the annular protrusion structure form a maze-like structure.

2. The extruder for cable processing as described in claim 1, characterized in that the inner surface of the second channel (241) is provided with a spiral protrusion (2411) along the axial direction.

3. The extruder for cable processing as described in claim 1, characterized in that it further includes a connecting plate (3), wherein the front die cavity (21) and the rear die cavity (22) are both fixedly installed on the surface of the connecting plate (3).

4. The extruder for cable processing as described in claim 3, characterized in that the rotating cavity (24) is provided with a first chamfered surface (242) along the outer circumferential direction at one end near the front die cavity (21), and a second chamfered surface (2111) is provided along the circumferential direction on the inner side of the first channel (211), and the first chamfered surface (242) and the second chamfered surface (2111) are in sliding fit.

5. The extruder for cable processing as described in claim 4, characterized in that it further includes a first thrust bearing (4), the inner ring of the first thrust bearing (4) being coaxially embedded in the first chamfered surface (242), and the outer ring of the first thrust bearing (4) being coaxially embedded in the second chamfered surface (2111).

6. The extruder for cable processing as described in claim 3, characterized in that a third chamfered surface (243) is provided along the outer circumference at one end of the rotating cavity (24) near the rear die cavity (22), and a fourth chamfered surface (2211) is provided along the circumference on the inner side of the groove (221), and the third chamfered surface (243) and the fourth chamfered surface (2211) are in sliding fit.

7. The extruder for cable processing as described in claim 6, characterized in that it further includes a second thrust bearing (5), the inner ring of the second thrust bearing (5) being coaxially embedded in a third chamfered surface (243), and the outer ring of the second thrust bearing (5) being coaxially embedded in a fourth chamfered surface (2211).

8. The extruder for cable processing as described in claim 3, characterized in that it further includes a combustion nozzle (6), the combustion nozzle (6) being fixedly mounted on the connecting plate (3), and the air outlet of the combustion nozzle (6) being positioned facing the outer surface of the rotating cavity (24).

9. A processing method of an extruder for cable processing based on any one of claims 1-8, characterized in that it includes the following steps: driving the wire to be conveyed at a constant speed to the discharge port (212) in the central tube (23), the screw extruder (1) extrudes the molten material into the extrusion cavity, rotating the drive component (25) to drive the rotating cavity (24) to rotate and circumferentially stirring the molten material located in the rotating cavity (24), the molten material is extruded from the annular outlet and then coated on the surface of the wire, and after cooling, a cable is obtained.